As published in the American Physical Society's Physical Review Letters: Nagahiro and Hayakawa "... investigate the condition for the bounce of circular disks which obliquely impacts on the fluid surface. An experiment [C. Clanet, F. Hersen, and L. Bocquet, Nature (London) 427, 29 (2004)] revealed that there exists a 'magic angle' of 20° between a disk's face and water surface in which the condition of the lowest impact speed necessary for a bounce is minimized. We perform a three-dimensional simulation of the disk-water impact by means of the smoothed particle hydrodynamics. Furthermore, we analyze the impact with a model of the ordinary differential equation (ODE).... The analysis with the ODE model gives us a theoretical insight into the 'magic angle' of stone skipping." Download the full article as a PDF or compressed PostScript file. Also, watch an mpg of their simulation.